Device for detecting bending and distortion of printed board assembly

Abstract

The invention discloses a device for detecting bending and distortion of a printed board assembly. The device comprises a base, a sliding block, a set screw, a fixed seat and a height measuring device, a guide rail is installed on the base, the sliding block can slide left and right on the guide rail, the fixing base can slide front and back on the sliding block, and the fixing base is used for fixing a printed board assembly. The height measuring device can detect the warping height. When the device is used for detecting the bow, the four corners of the printed board assembly are fixed by the fixing seats, the triangular positions of the printed board assembly are fixed by the fixing seats when the distortion is detected, the warping height of the printed board assembly is measured, and the bow or distortion degree is calculated through a formula. The problem that the warping degree of the double-sided assembled printed board assembly cannot be accurately and quickly measured by a traditional measurement method is solved, and the detection device is simple to operate and can quickly and accurately measure the bow and the warping degree of the printed board assembly.

Description

Technical Field

[0001] The invention relates to the technical field of electronic assembly. Background Art

[0002] Printed circuit board warping can generally be divided into bowing and twisting. Bowing means that when the printed circuit board is placed on the platform, the four corners can touch the platform, but the middle is convex; twisting means that when the printed circuit board is placed on the platform, the printed circuit board is deformed into an irregular shape, and when any three feet are pressed, the remaining corner is warped. Before the printed circuit board is assembled, if the printed circuit board has warping, defects such as cold solder joints will occur during the assembly of components, resulting in component failure. GJB362B-2009 "General Specifications for Rigid Printed Circuit Boards" stipulates the maximum bowing and twisting of printed circuit boards. After the printed circuit board is assembled, if the printed circuit board assembly with soldered components has warping, it will generate greater stress on the solder joints during subsequent installation and tightening, affecting the reliability of the solder joints. GB / T4588.3 "Design and Use of Printed Circuit Boards" requires that the warping degree of the printed circuit board assembly with soldered components should not affect the subsequent assembly, and should not increase the mechanical load between the components and the solder joints. The above national standard requires that the detection method should be carried out in accordance with the calculation method or plug gauge method in GB / T4677-2002 "Printed Circuit Board Test Method". This method can quickly and conveniently detect bare boards or single-sided assembled boards, but double-sided assembled boards have components soldered on both sides, which will interfere with the measurement platform and cannot form a plane as a reference. It is time-consuming and laborious to detect the warpage. With the development of assembly technology, the use of double-sided assembled boards is becoming more and more widespread, and a method that can accurately and quickly measure the warpage of printed circuit board components is needed.

[0003] Invention patent CN102901434B proposes a detection device and a detection method, which uses an auxiliary device to form an imaginary reference plane with three corners on the printed circuit board, measures the warping height of the last corner, and finally calculates the distortion in the warping, but cannot measure the bow in the warping.

[0004] Therefore, designing a method that can accurately and quickly measure the bow and twist of printed circuit board components has become a problem that the industry needs to solve. Summary of the invention

[0005] The present invention proposes a detection device for the bow and twist of a printed circuit board assembly, which solves the problem that traditional measurement methods cannot measure the warpage of a double-sided assembled printed circuit board assembly. The detection device is simple to operate and can quickly and accurately measure the bow and twist of the printed circuit board assembly.

[0006] In order to achieve the above technical objectives, the present invention is implemented through the following technical solutions:

[0007] A device for detecting the bow and distortion of a printed circuit board assembly comprises a base, a slider, a set screw, a fixing seat and a height measuring device; the slider is mounted on the base and fixed by the set screw; the fixing seat is mounted on the slider and fixed by the set screw; the height measuring device is mounted on the base by a threaded connection.

[0008] Furthermore, in the above device, a guide rail is installed on the base, and the slider can slide left and right on the guide rail.

[0009] Furthermore, in the above device, the fixing seat is provided with a set screw for fixing the printed circuit board assembly.

[0010] Furthermore, in the above device, the height measuring device includes a fixed rod, a cantilever, and a digital altimeter. The fixed rod is installed on the base through a threaded connection. The swing arm can move up and down on the fixed rod and is fixed by a set screw. The digital altimeter is connected to the swing arm through a threaded connection.

[0011] Furthermore, in the above device, the swing arm has two brackets connected by a pin, and the two brackets can rotate freely.

[0012] Furthermore, in the above device, the accuracy of the digital altimeter should reach 0.01mm.

[0013] The beneficial effects of the present invention are: a detection device for the bow and twist of a printed circuit board assembly is proposed, which solves the problem that traditional measurement methods cannot accurately and quickly measure the warpage of a double-sided assembled printed circuit board assembly. The detection device is simple to operate and can quickly and accurately measure the bow and twist of the printed circuit board assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 FIG. 1 is a schematic diagram of using the device to measure the distortion of a printed circuit board assembly.

[0015] Figure 2 FIG. 1 is a schematic diagram of using the device to measure the bow of a printed circuit board assembly.

[0016] Numbers in the figure: 1-base; 11-guide rail; 2-slider; 3-fastening screw; 4-fixed seat; 5-height measuring device; 51-fixed rod; 52-swing arm; 53-digital display height gauge; 6-printed circuit board assembly. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0018] Example 1

[0019] Measuring the deflection of a printed circuit board assembly includes the following steps:

[0020] First, place the detection device base 1 on the standard platform, move the slider 2 to the appropriate position on the guide rail 11 according to the size of the printed circuit board assembly 6, move the fixing seat 4 to the appropriate position on the slider 2, tighten the set screws 3, and fix the printed circuit board assembly 6 at any triangular position; second, adjust the height measuring device 5, move the swing arm 52 to the appropriate height on the fixing rod 51, and rotate the swing arm 52 to make the digital display altimeter 53 located above the unfixed corner of the printed circuit board assembly 6, and adjust the digital display altimeter 53 to zero according to the plane of the fixing seat 4; third, use the digital display altimeter 53 to measure the maximum warping height of the printed circuit board assembly; fourth, calculate the distortion of the printed circuit board assembly by the formula Q=(Hh) / L, where H is the maximum warping height, h is the thickness of the printed circuit board, and L is the diagonal length.

[0021] Example 2

[0022] Measuring the bow of a printed board assembly includes the following steps:

[0023] First, place the detection device base 1 on the standard platform, move the slider 2 to the appropriate position on the guide rail 11 according to the size of the printed circuit board assembly 6, move the fixing seat 4 to the appropriate position on the slider 2, tighten the set screws 3, and fix the four corners of the printed circuit board assembly 6; second, adjust the height measuring device 5, move the swing arm 52 to the appropriate height on the fixing rod 51, and rotate the swing arm 52 to make the digital display height gauge 53 located in the middle of the bending edge of the printed circuit board assembly 6, and adjust the digital display height gauge 53 to zero according to the plane of the fixing seat 4; third, use the digital display height gauge 53 to measure the maximum warping height of the printed circuit board assembly; fourth, calculate the distortion of the printed circuit board assembly by the formula Q=(Hh) / L, where H is the maximum warping height, h is the thickness of the printed circuit board, and L is the length of the bending edge.

[0024] The above description is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A device for detecting bow and twist of a printed circuit board assembly, characterized in that: The device comprises a base, a slider, a set screw, a fixing seat and a height measuring device; the slider is installed on the base and fixed by the set screw; the fixing seat is installed on the slider and fixed by the set screw; the height measuring device is installed on the base by threaded connection.

2. A printed circuit board assembly bow and twist detection device according to claim 1, characterized in that: A guide rail is installed on the base, and the slide block can slide left and right on the guide rail.

3. A printed circuit board assembly bow and twist detection device according to claim 1, characterized in that: The fixing seat is provided with a set screw for fixing the printed circuit board assembly.

4. A printed circuit board assembly bow and twist detection device according to claim 1, characterized in that: The height measuring device includes a fixed rod, a cantilever, and a digital altimeter. The fixed rod is installed on the base through a threaded connection. The swing arm can move up and down on the fixed rod and is fixed by a set screw. The digital altimeter is connected to the swing arm through a threaded connection.

5. A printed circuit board assembly bow and twist detection device according to claim 4, characterized in that: The rotary arm has two brackets connected by a pin shaft, and the two brackets can rotate freely.

6. A printed circuit board assembly bow and twist detection device according to claim 4, characterized in that: The accuracy of the digital altimeter should reach 0.01mm.

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